PGRMC1 is a progesterone receptor component of 195 aa with a 26 residue N terminal hydrophobic region and no N terminal glycosylation site. It has an overall homology of 50% with PGRMC2 but their C terminal regions have a 68% homology, including a highly conserved 58 residue sequence.PGRMC1 is a heme bind proteins that is up-regulated in several cancers. In breast tumors, PGRMC1 is associated with hypoxia estrogen receptor-negative status. PGRMC1 is also shown to stimulate AKT phosphorylation and is known to stabilise the EGFR receptor tyrosine kinase.